In the High-Definition Multimedia Interface (HDMI) specification (e.g., version 1.4b released on Oct. 11, 2011) of image source devices such as DVD/STB or image sink devices such as TV that transmits or receives the signals through three digital transmission lines, eight bits for each pixel signal of three colour components (R, G, B) of an image signal and two bits for each of control signals to be transmitted during a blanking period of the image signal are converted (encoded) into ten bits, respectively, to be transmitted serially over the three-channel transmission lines. This encoding scheme is referred to as Transmission Minimized Differential Signal (TMDS).
Large-scale integrated circuits manufactured by employing a micro-lithography can be preferably utilized so as to reduce the cost of a high-speed serial driving circuit of a HDMI transmitting module.
However, in the HDMI specification, when transmitting signals serially between an HDMI transmitting module and an HDMI receiving module, which are connected via an HDMI cable, a scheme of DC coupling between a termination resistor of the HDMI receiving module pulled up to 3.3V and the HDMI transmitting module is utilized. The high speed serial driving circuit of the HDMI transmitting module is required to withstand the voltage characteristics corresponding to the pulled up voltage.
Therefore, it is difficult to utilize a large scale integrated circuit having a low withstand voltage characteristics as the high speed serial driving circuit of the HDMI transmitting module.
Accordingly, the embodiments of the present invention intend to provide a signal transmission apparatus and a signal transmission method in which the signals can be transmitted to a signal receiving device with suppressing the influence of the voltage of the signal receiving device which is pulled up to a predetermined voltage.